The invention relates to a method for producing a connection between an insert element with a tube-like part by means of flanging.
Such a method is known, for example, from DE 40 13 032 A1. With this method the insert element is embodied as a lid, which is introduced from a front end of a tube-like part embodied as a housing. The lid comes to rest in the direction of the longitudinal axis of the housing against a detent in order to assure exact positioning in the direction of the longitudinal axis. Subsequently the edge of the housing which projects past the lid in the direction of the longitudinal axis is flanged radially inward in relation to the longitudinal axis of the housing, while being plastically deformed, so that it grips around the outer edge of the lid and rests against the lid in the direction of the longitudinal axis of the housing. The lid is then fixed in place between the detent and the flanged edge of the housing in the direction of the longitudinal axis. During flanging of the edge of the housing, the housing is pressed together in the direction of its longitudinal axis and after flanging springs back. The holding power of the flange is reduced and, under unfavorable circumstances can even become zero.
A method is furthermore known in which the maintenance of the holding power of the flange is assured. To this end the tube-like part has an area whose exterior diameter is enlarged in respect to the remaining area over at least a portion of its circumference at its one end, into which the insert element is to be introduced. To produce the flange, a ring-shaped tool element is pushed over the tube-like part from its other end, whose cross section is less than the area of the tube-like part of enlarged exterior cross section and is at least as large as the exterior cross section of the remainder of the tube-like part. A relative movement in the direction of the longitudinal axis takes place between the tool element and the tube-like part, so that the tool element is moved over the area of the tube-like part with the enlarged exterior cross section and this area is pushed radially inward in relation to the longitudinal axis while being plastically deformed. While the ring-shaped tool element is moved over the area of the tube-like part with an enlarged exterior cross section, a tensile force simultaneously acts on the tube-like part, so that the holding power on the insert element is even increased by the spring-back of the tube-like part following the production of the flange, and in this way an assured fastening of the insert element in the tube-like part is achieved.
The area which has an enlarged exterior cross section in relation to its remaining area, which is formed on the one end in which the pump element is inserted, requires several work steps for its production, for example by deep drawing.